Patent GB-1378276-A (GB)
Title: Apparatus for fueling an internal combustion engine
IPC: F02M1/16
Filed: 1973-02-20
Abstract: 1378276 Fueling an internal combustion engine STANDARD OIL CO 20 Feb 1973 [28 Feb 1972] 8268/73 Heading F1B A method of starting and running an I.C. engine on petrol, comprising the steps of, (a) separating low boiling petrol components from higher boiling petrol components of the petrol (b) mixing the low boiling components with air in a controlled manner to produce a gaseous fuel having a predetermined airfuel ratio (c) at start-up of the engine, by-passing the engine's carburetter and fueling the engine directly through the fuel intake system with the gaseous fuel and (d) in response to predetermined operating conditions of the engine, discontinuing fueling the engine with the gaseous fuel and then fueling the engine with petrol through the engine's carburetter. An engine 11 is fed by a conventional carburetter 12 for normal running, but for starting and during warm-up, is supplied with a stoichiometric, or leaner than stoichiometric air-fuel mixture, by a system 14, the fuel being the lower boiling fractions of the petrol which have been extracted from the fuel in the vehicle's tank by stripping with air. The inlet 21 to fuel tank 20 extends about two inches into the tank so that there is always an air space 32 above the fuel. A pipe 36, open to atmosphere through a filter 38, admits air which bubbles through the petrol and produces a mixture of air and fuel vapour in the space 32. This mixture, is mixed with additional air in a valve 24 and passes along a pipe 40, past a driver controlled throttle valve 46 to the induction pipe of the engine, at a point downstream of a valve 47 which is closed to isolate the conventional carburetter 12 from the induction pipe. The pipe 40 contains two further ganged valves 48 and 50, a solenoid-operated vent valve 164, a flame trap 52 and a safety valve 56. The ratio of fuel to air is held constant by a controller 44, Fig.6, which comprises a tube 134 which dips into the petrol, a bellows 136 attached to the bottom of the tube and connected by a line 138 to a chamber containing a diaphragm 140, which is biased by a spring and which is connected by a rod to a plate 66 forming part of the valve 24. A solenoid 142 is mounted on the bellows 136 and is connected by a spring to a closure plate 146 which seals the end of the tube when the solenoid is energized. Simultaneously the bellows is extended and forms a space above the trapped petrol, the vapour pressure in this space acting on the diaphragm and moving the plate 66 to a position dependent on the vapour pressure of the petrol, which varies in accordance with changes in the composition and temperature of the petrol. The valve 24, Fig.2, consists of three blocks 60, 61 and 62, a closure plate 68, a swinger plate 64 and the sliding plate 66. In the block 60 are an air inlet 76 and an air-fuel mixture inlet 74. In the block 61 are a triangular port 86, a quadrangular port 88, a recess 82 in which the plate 64 can swing about a pivot 92 and a cavity 84 in which the plate 66 can slide. As the plate 64 moves it permits a greater or smaller flow through the ports 86 and 88, but due to their shape, the ratio of the flows through the individual ports remains constant. The plate 66 as it is moved to different positions across the block 61 progressively uncovers one port while increasingly covering the other port and thereby changes the ratio of air to fuel in the mixture which leaves the valve by the pipe 40. When the engine is to be started, electrical switches are moved to the closed position and cause the valves 47, 46, 48 and 50 to move to the positions shown in Fig.1, and the valve 164 to be closed. The engine is supplied through the system 14 until the engine or catalyst system for treating exhaust gas reach a predetermined temperature, after which the conventional carburetter is used.